Applications Of Derivatives Question 177

Question: If a spherical balloon has a variable diameter $ 3x+\frac{9}{2} $ , then the rate of change of its volume with respect to x is

Options:

A) $ 27\pi {{(2x+3)}^{2}} $

B) $ \frac{27\pi }{16}{{(2x+3)}^{2}} $

C) $ \frac{27\pi }{8}{{(2x+3)}^{2}} $

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

Radius of balloon = $ r=\frac{3}{4}(2x+3)\Rightarrow \frac{dr}{dx}=\frac{3}{2} $

$ \therefore $ Rate of change in volume = $ 4\pi {{( \frac{3}{4} )}^{2}}{{(2x+3)}^{2}}.\frac{3}{2} $

$ =\frac{27\pi }{8}{{(2x+3)}^{2}} $ .